陇东地方牛种遗传多样性研究

Study on the genetic diversity of Longdong native cattle

对陇东地方牛种及其与秦川牛和南德温牛杂交群体共计113个个体线粒体D-loop区461 bp序列进行多态性分析,结果表明,3个群体该区域A+T含量(64.2%)明显高于G+C含量(35.8%),表现出明显的碱基偏倚;3个群体核苷酸变异率介于0.42%和3.27%之间,陇东牛和南德温牛杂交群体核苷酸变异率最高;核苷酸变异类型以转换为主,转换占核苷酸多态位点的90.94%,其次为颠换,占4.59%,同样表现出明显的碱基替换偏倚;3个群体核苷酸岐异度介于0.008 95和0.029 06之间,遗传距离介于0.000 15和0.008 36之间,陇东地方牛及其与秦川牛的杂交群体核苷酸歧异度和遗传距离最小。

A total of 461 bp of the mitochondrial D-loop region was sequenced and analyzed in 113 individuals from 3 populations,Longdong cattle,Longdong cattle × Qinchuan cattle hybrid population and Longdong cattle × Nandewen cattle hybrid population.The results indicated the content of A ＋T（64.2%） in D-loop region in all 3 populations was significantly higher than that of G ＋C（35.8%）,showing the base bias;Nucleotide mutation rate in 3 populations was between 0.42% and 3.27%,and the nucleotide mutation rate in Longdong cattle and Longdong cattle × Nandewen cattle hybrid population was the highest;Transition was in the majority with 90.94% in nucleotide polymorphism site,followd by transversion with 4.59%,also showing base substitution bias;the nucleotide divergence in 3 populations was between 0.008 95 and 0.029 06,the genetic distance was between 0.000 15 and 0.008 36,and the nucleotide divergence and net genetic distance beween Longdong cattle and Longdong cattle × Qinchuan cattle hybrid population was the smallest.